Paul DeJong needs a readjustment

On Tuesday night, the St. Louis Cardinals defeated the rival Cubs 5-3. In the process, Paul DeJong went 1-5 with a home run and four strikeouts, raising his wRC+ from 115 to 120 and his strikeout rate from 41.0% to 43.9%. A 120 wRC+ is very good; striking out nearly half the time is very bad.

As has been well documented, I have serious concerns regarding DeJong’s ability to sustain even average value at the plate. Given his propensity to strike out and aversion to taking walks, I see a guy who likely settles in as an 85 to 95 wRC+ hitter. If he’s an above average defender at short, maybe that’s fine. Today, however, I’m more interested in this:

Source: Fangraphs

In the graph above, I plotted the change in hitters “pulled fly ball %” (FB Pull%; min. 10 fly balls in 2018 and 60 in 2017) against their change in contact rate (Contact%). There’s no relationship between these two metrics, at least not as they are presented here. But Paul DeJong stands out. Through April 17th, he owns the third biggest increase in FB Pull%. Through April 17th, he owns the second biggest decrease in Contact%. He’s way out there on his own, and no one else is close.

Generally, hitters seeking to do more damage with their contact try to pull more of their fly balls. Pulled fly balls are the most valuable type of contact and if a hitter can increase his FB Pull% while keeping the rest of his offensive profile relatively stable, he’s very likely to improve. Brian Dozier broke out in 2014 by driving more of his fly balls to the pull-side. Yadier Molina has reinvigorated himself at the plate by doing the same. Mookie Betts is pulling almost all his fly balls on his way to becoming Baseball's Best Hitter. It appears that, despite a successful rookie campaign, Paul DeJong is attempting to follow in their footsteps.

Unfortunately, DeJong has so far been unable to make contact at a dignified level with this approach. His Contact% has tanked from a respectable 74.2% in 2017 to a dismal 56.4% in 2018. His Contact% is the lowest among qualified hitters this year, and since 2002 no qualified hitter has completed a season with a contact rate below 59%. Paul DeJong’s current whiff rate is historic. Thus, while his contact quality has improved over 2017, his expected value at the plate has deteriorated. DeJong is seeking better contact at the expense of more whiffs, and so far it isn’t really working.

If DeJong is trying to implement a new approach, it’s a near certainty that pitchers will catch on and find holes to attack. In fact, it’s possible that they already have:

The heatmap shows DeJong’s whiffs so far in 2018 and the dots represent all the balls thrown to DeJong by Cubs pitchers on Tuesday. They overlap almost completely – the book on DeJong is already out. It’s clear that DeJong needs to make another adjustment. Hopefully his ability to do damage on-contact buys him the time.